The present application is based on and claims priority to Japanese Patent Application No. 11-130667 filed May 11, 1999, the entire contents of which is hereby expressly incorporated by reference.
1. Field of the Invention
The present invention is directed to an outboard drive motor for a watercraft, and in particular, a grommet assembly for the engine cover of the outboard motor drive.
2. Description of Related Art
Outboard motors generally include a powerhead that includes a powering internal combustion engine and a surrounding protective cowling. The cowling is provided around the engine so as to provide a neater appearance, to protect the engine from foreign materials, as well as for aerodynamic considerations. Of course, the protective cowling typically includes a number of apertures. For example, the cowlings of outboard motors typically include at least one air inlet arrangement configured to allow combustion air to enter the protective cowling while preventing or attenuating the influx of water into the protective cowling. Additionally, the protective cowling of outboard motors typically includes an aperture through which a plurality of flexible conduits and cables extend, such as for example, fuel lines, oil lines, throttle control lines, transmission control lines and the like.
Watercraft which use outboard motors as a propulsion device typically include a fuel tank disposed within the hull of the watercraft and a fuel supply line that connects the fuel tank with a fuel system of the engine within the protective cowling of the outboard motor. There may also be a lubrication system which includes a remotely positioned tank and which may require delivery and/or return conduits that pass through the protective cowling. Various bowden wire actuators or other types of flexible transmitters may also be required. For example, throttle and transmission control lines typically extend through the protective cowling for operating the throttle and transmission, respectively. Additionally, battery cable may extend through the grommet to connect the battery with a generator and/or a starter motor.
In all these instances, it is desirable to provide an arrangement wherein the various conduits, transmitters or cables, hereinafter referred to in both the specification and the claims as xe2x80x9cflexible conduits,xe2x80x9d pass through openings in the protective cowling and the cowling openings are sealed. Normally, elastic sealing grommets are employed for this purpose. However, if a separate grommet is provided for each flexible conduit, then the construction becomes rather objectionable in appearance. Furthermore, the use of such plural holes and grommets in the protective cowling gives rise to an objectionable construction and one which is expensive to manufacture and more difficult to service.
For example, it is frequently necessary to disassemble and reassemble the arrangement, and it is difficult to feed these various flexible elements through the grommets, particularly if they are in place in the protective cowling. Frequently, attempts at such installation and removal damage the flexible conduits.
It is also desirable that the flexible conduit, protective cowling, and grommet provide a tight seal to prevent water from inadvertently seeping into the interior of the protective cowling and damaging the conduits and components therein. Desirably, flexible conduits pass through the protective cowling at a forward end of the power head of the outboard of the motor. Thus, the grommet can be subjected to significant impingement of wind during operation of the outboard motor in some applications. Such impingement can carry water into the power head if the grommet does not adequately seal against the flexible conduits.
With reference to FIG. 1, a known grommet assembly is shown. The grommet assembly 2 includes a grommet 4, a flexible sleeve 6, and a band clamp 8. Although not illustrated, the grommet 4 is constructed to be installed through an aperture in an outboard motor cowling. Additionally, the grommet 4 includes a number of longitudinally extending passages forming seals with flexible conduits extending therethrough, as is typical in some outboard motors. Additionally, the flexible conduits extend through the flexible sleeve 6. In order to generate a seal between the flexible sleeve 6 and the grommet 4, the band clamp 8 is tightened. Thus, the sleeve 6 provides further protection for the flexible conduits extending through the grommet 4 and provides additional wind protection for the seal between the grommet 4 and the flexible conduits.
One aspect of the present invention includes the realization that known grommet assemblies have proved to be inadequate. For example, with reference to FIG. 2, it has been found that where a band clamp is used, such as band clamp 8, to compress the flexible sleeve 6 radially inwardly, in the direction indicated by the arrows A, the grommet 4 is undesirably deformed. It has further been found that users can overtighten the band clamp 8 and deform the grommet 4 to such an extent that the sleeve 6 readily falls off the grommet 4. Additionally, it has been found that if the grommet 4 is constructed of a more rigid material, the connection of the sleeve 6 to the grommet 4 may be improved, but the ability of the grommet 4 to create a seal with the flexible conduits is reduced.
A need therefore exists for a grommet assembly for an engine cover of a marine engine that has an incresead life span. It is desirable that the assembly be less likely to be damaged through user intervention and be simple to manufacture. Additionally, the grommet assembly should be constructed in such a manner that the grommet may be formed of an elastomeric or similar material such that the ability of the grommet to seal with flexible conduits extending therethrough is maintained.
According to another aspect of the invention, a grommet assembly for a marine propulsion unit which has a plurality of flexible conduits extending through an engine cover comprises a flexible grommet having an outer surface and at least one passage extending longitudinally therethrough. The grommet includes first and second open ends and a step disposed on the outer surface between the first and second ends. The assembly also includes a flexible sleeve that has an outer surface and at least one step disposed on the outer surface. A first end of the sleeve is configured to fit over a portion of the grommet between the first end and the step. The assembly also includes a connector having first and second engaging devices, the first engaging device configured to engage the step disposed on the grommet and the second engaging device configured to engage the step disposed on the sleeve. By constructing the grommet assembly with a connector that is configured to engage a step disposed on a grommet and a step disposed on the flexible sleeve, the present grommet assembly provides improved engagement between the grommet and the flexible sleeve.
As noted above, known devices have caused a drawback by relying on the compression of the flexible sleeve against the grommet in order to engage the sleeve with the grommet. However, as noted above with respect to FIG. 2, it has been found that users often overtighten the band 8 used to engage the sleeve 6 with the grommet 4 and thus deform the grommet 4. Such deformation of the grommet 4 eventually leads to loosening and dislodgment of the sleeve 6. Thus, by providing a connector that engages a step disposed on the grommet and the step disposed on the sleeve, the present grommet assembly provides engagement between the sleeve and the grommet without relying solely on a frictional force generated by a radially inward compression of the sleeve against the grommet.
Further aspects, features, and advantages of the present invention will become apparent from the detailed description of the preferred embodiment which follows.